There are many scientific studies that show that Dogs need their hormones for proper development. For this reason you should wait until a dog is fully grown to have these procedure done.
Both of these Labs are from the same Litter. One was neutered at 6 months and the other after his second Birthday. You can see that the late Neuter dog is huskier and fully developed
Please do your research and consult with your Vet and breeder. There are many options for spay and neuter many Leaving the dog's hormone producing organs in place
It is important to remove a female dogs Uterus, 25% of female dogs get pyometra – a serious disease that affects the uterus and cervix and often requires emergency surgery. A hysterectomy that removes ALL the cervix and uterine tiss